The Siam Cement Group (SCG), a major industrial conglomerate in Thailand, will soon resume operation of the $5-billion Long Son Petrochemicals (LSP) complex in Vietnam.
In early March 2026, SCG informed the Stock Exchange of Thailand (SET) of the temporary suspension of operations at Rayong Olefins (ROC) in Thailand. Later, SCG said it would suspend operations at LSP in Vietnam in May.
For the two suspensions, SCG clarified that geopolitical tensions around the Strait of Hormuz disrupted logistics and created severe procurement bottlenecks for essential feedstocks, namely naphtha and propane.
In mid-September, ROC resumed operations, after completing a full review of its operational and safety aspects.
Also in September, SCG disclosed an update on a planned joint venture with PTT Global Chemical (PTTGC), a unit of Thailand’s state-controlled energy group PTT, to combine their olefins and polyolefins businesses. The two companies have entered confirmatory due diligence.
As the new venture would produce the same products as LSP, the move prompted speculation about the Vietnamese plant’s future.
Answering inquiry with the Vietnamese media, SCG clarified that the potential joint venture currently under discussion between SCG and PTTGC covers olefins and polyolefins assets in Thailand and does not include LSP.
At LSP, SCG have moved beyond the preservation shutdown phase and entered an active project execution and transformation phase. SCG is using this period actively to upgrade the plant, improve feedstock flexibility, accelerate digital and AI transformation, and strengthen the readiness for restart.
LSP is targeting the restart of LSP operations in Q2/2027, following a planned five-month Turnaround beginning on November 1, 2026.
Upon completion, the plant can Ethane for 70 percent of in its feedstock mix.
Long Son Petrochemicals (LSP) is SCG’s flagship petrochemical investment in Vietnam. It is also the country’s first fully integrated petrochemical complex, built near Ho Chi Minh City for $5 billion and wholly owned by SCG Chemicals.
It began full commercial operations on September 30, 2024, with annual capacity of about 950,000 tons of ethylene and 400,000 tons of propylene.
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